Saucon Valley Rail Trail from Reading Drive parking lot to N end in Hellertown, not far from Goodman fields where Lehigh sports teams play. My side excursion near the N end was apparently an
iron works at one point but I didn't explore trails much there because I wasn't sure what was there, and had a long way to go to return to the car.
Gorgeous day; lots of folks on the trail. About mid to upper 40s when I started and mid to upper 50s when I finished.
At a park I passed by (which has a basketball court, playground, and BMX area and hosts the outdoor Farmers Market in season), I saw a woman standing outside the portable toilet and as I passed by I heard a small voice say "How do you flush it?"
Her reply: "You don't." :-)